9. Garet Hil

"When we started our nonprofit in 2007, most kidney transplant centers used loops, which involve a simple kidney swap between two or more pairs of people. The alternative, kidney chains, requires a Good Samaritan to donate to a stranger, enabling a chain of transplants to occur.

"Since I come from a software background, our innovation was to create an algorithm that combined loops and chains to maximize the number of exchanges. After five years and seven incarnations, our latest algorithm, created with Harvard and MIT professors, found up to 167% more matches than the previous one.

"For the first three years, my wife and I ran the National Kidney Registry without financial support from transplant centers, with no revenue model in sight. Today, we facilitate more paired exchange kidney transplants than any organization in the world. But throughout that time, finding Good Samaritan donors was never a problem. We simply helped them fulfill their desires."

Timeline

2007

Founds the National Kidney Registry

2007

Daughter received her new kidney from her 23-year-old cousin

2011

Helps design the SMELAC algorithm, which is 167% more effective in facilitating a kidney exchange than the previous algorithm

Joins the United States Marine Corps at age 17

Receives MBA from the Wharton School of Business at the University of Pennsylvania

Leads a $5 million dollar acquisition and turnaround of a digital printing company; after 11 years, sold it for $1.1 billion